From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-89570: cxl/mce: Make the MCE notifier per-region
Date: Fri, 11 Sep 2026 21:44:19 +0200 [thread overview]
Message-ID: <2026091125-CVE-2026-89570-445f@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
cxl/mce: Make the MCE notifier per-region
Flavien Solt reported lifetime issues with the CXL MCE notifier, which
can lead to NULL dereferences and use-after-free in the MCE handler.
The notifier was registered per memory device and stored in 'struct
cxl_memdev_state', even though it only needs the region state (the
region's SPA range and its extended linear cache size).
Instead of keeping the memory device and endpoint alive, the correct fix
is to move the notifier into 'struct cxl_region' and register it from
cxl_region_probe() as it should be a per-region notifier. Setup the
registration to only happen for regions that have an extended linear
cache as that is the only current usage.
Remove cxl_port_get_spa_cache_alias() as it is now dead code.
[ dj: Update dev_warn() when notifier fails due to kconfig. (Ben) ]
The Linux kernel CVE team has assigned CVE-2026-89570 to this issue.
Affected and fixed versions
===========================
Issue introduced in 6.15 with commit 516e5bd0b6bf4ae1ad072df637b428a737c3c870 and fixed in 6.18.51 with commit 5563db13c9528a56c7161260ec75ec8690dc5608
Issue introduced in 6.15 with commit 516e5bd0b6bf4ae1ad072df637b428a737c3c870 and fixed in 7.2.4 with commit 491d8c9ac98d55073bda778f88a5248d4cce3fa0
Issue introduced in 6.15 with commit 516e5bd0b6bf4ae1ad072df637b428a737c3c870 and fixed in 7.3-rc1 with commit 775d0f4558f4cec0ee0c8966595d1add1791f36e
Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.
Unaffected versions might change over time as fixes are backported to
older supported kernel versions. The official CVE entry at
https://cve.org/CVERecord/?id=CVE-2026-89570
will be updated if fixes are backported, please check that for the most
up to date information about this issue.
Affected files
==============
The file(s) affected by this issue are:
drivers/cxl/core/mbox.c
drivers/cxl/core/mce.c
drivers/cxl/core/region.c
drivers/cxl/cxl.h
drivers/cxl/cxlmem.h
Mitigation
==========
The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes. Individual
changes are never tested alone, but rather are part of a larger kernel
release. Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all. If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
https://git.kernel.org/stable/c/5563db13c9528a56c7161260ec75ec8690dc5608
https://git.kernel.org/stable/c/491d8c9ac98d55073bda778f88a5248d4cce3fa0
https://git.kernel.org/stable/c/775d0f4558f4cec0ee0c8966595d1add1791f36e
reply other threads:[~2026-09-11 19:56 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2026091125-CVE-2026-89570-445f@gregkh \
--to=gregkh@linuxfoundation.org \
--cc=cve@kernel.org \
--cc=gregkh@kernel.org \
--cc=linux-cve-announce@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.